Protection from insect infestation may be accomplished by a combination of measures including temperature reduction and occasional fumigation. Irradiation has also been proposed to control insect infestation in cereals and other products but the cost of this expensive and controversial technology is prohibitive and in any event is limited to off-farm use.
Europe went through equally dramatic changes after 1955. Cases 1 and 2 show that the labor effects of mechanization depend on the alternatives available to the economy. The Indian Punjab provides an opposite example. The green revolution initiated in the mid-1960s led to sharply increased demand for labor, which caused a big rise in real wages around 1968 (Gupta and Shangari 1979).